[PATCH v2 0/6] media token resource framework

2014-10-14 Thread Shuah Khan
Add media token device resource framework to allow sharing
resources such as tuner, dma, audio etc. across media drivers
and non-media sound drivers that control media hardware. The
Media token resource is created at the main struct device that
is common to all drivers that claim various pieces of the main
media device, which allows them to find the resource using the
main struct device. As an example, digital, analog, and
snd-usb-audio drivers can use the media token resource API
using the main struct device for the interface the media device
is attached to.

This patch series consists of media token resource framework
and changes to use it in dvb-core, v4l2-core, au0828 driver,
and snd-usb-audio driver.

With these changes dvb and v4l2 can share the tuner without
disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
vlc audio capture option, arecord/aplay during development to
identify v4l2 vb2 and vb1 ioctls and file operations that
disrupt the digital stream and would require changes to check
tuner ownership prior to changing the tuner configuration.
vb2 changes are made in the v4l2-core and vb1 changes are made
in the au0828 driver to encourage porting drivers to vb2 to
advantage of the new media token resource framework with changes
in the core.

In this patch v2 series, fixed problems identified in the
patch v1 series. Important ones are changing snd-usb-audio
to use media tokens, holding tuner lock in VIDIOC_ENUMINPUT,
and VIDIOC_QUERYSTD.

Shuah Khan (6):
  media: add media token device resource framework
  media: v4l2-core changes to use media token api
  media: au0828-video changes to use media token api
  media: dvb-core changes to use media token api
  sound/usb: pcm changes to use media token api
  media: au0828-core changes to create and destroy media

 MAINTAINERS |2 +
 drivers/media/dvb-core/dvb_frontend.c   |   14 +-
 drivers/media/usb/au0828/au0828-core.c  |   23 +++
 drivers/media/usb/au0828/au0828-video.c |   42 +-
 drivers/media/v4l2-core/v4l2-fh.c   |7 +
 drivers/media/v4l2-core/v4l2-ioctl.c|   61 
 include/linux/media_tknres.h|   50 +++
 lib/Makefile|2 +
 lib/media_tknres.c  |  237 +++
 sound/usb/pcm.c |9 ++
 10 files changed, 445 insertions(+), 2 deletions(-)
 create mode 100644 include/linux/media_tknres.h
 create mode 100644 lib/media_tknres.c

-- 
1.7.10.4

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Re: [PATCH v2 0/6] media token resource framework

2014-10-15 Thread Takashi Iwai
At Tue, 14 Oct 2014 08:58:36 -0600,
Shuah Khan wrote:
> 
> Add media token device resource framework to allow sharing
> resources such as tuner, dma, audio etc. across media drivers
> and non-media sound drivers that control media hardware. The
> Media token resource is created at the main struct device that
> is common to all drivers that claim various pieces of the main
> media device, which allows them to find the resource using the
> main struct device. As an example, digital, analog, and
> snd-usb-audio drivers can use the media token resource API
> using the main struct device for the interface the media device
> is attached to.
> 
> This patch series consists of media token resource framework
> and changes to use it in dvb-core, v4l2-core, au0828 driver,
> and snd-usb-audio driver.
> 
> With these changes dvb and v4l2 can share the tuner without
> disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
> vlc audio capture option, arecord/aplay during development to
> identify v4l2 vb2 and vb1 ioctls and file operations that
> disrupt the digital stream and would require changes to check
> tuner ownership prior to changing the tuner configuration.
> vb2 changes are made in the v4l2-core and vb1 changes are made
> in the au0828 driver to encourage porting drivers to vb2 to
> advantage of the new media token resource framework with changes
> in the core.
> 
> In this patch v2 series, fixed problems identified in the
> patch v1 series. Important ones are changing snd-usb-audio
> to use media tokens, holding tuner lock in VIDIOC_ENUMINPUT,
> and VIDIOC_QUERYSTD.

Just took a quick glance over the patches, and my first concern is why
this has to be lib/*.  This means it's always built-in as long as this
config is enabled (and will be so on distro kernel) even if it's not
used at all.


thanks,

Takashi
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Re: [PATCH v2 0/6] media token resource framework

2014-10-15 Thread Shuah Khan
On 10/15/2014 10:48 AM, Takashi Iwai wrote:
> At Tue, 14 Oct 2014 08:58:36 -0600,
> Shuah Khan wrote:
>>
>> Add media token device resource framework to allow sharing
>> resources such as tuner, dma, audio etc. across media drivers
>> and non-media sound drivers that control media hardware. The
>> Media token resource is created at the main struct device that
>> is common to all drivers that claim various pieces of the main
>> media device, which allows them to find the resource using the
>> main struct device. As an example, digital, analog, and
>> snd-usb-audio drivers can use the media token resource API
>> using the main struct device for the interface the media device
>> is attached to.
>>
>> This patch series consists of media token resource framework
>> and changes to use it in dvb-core, v4l2-core, au0828 driver,
>> and snd-usb-audio driver.
>>
>> With these changes dvb and v4l2 can share the tuner without
>> disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
>> vlc audio capture option, arecord/aplay during development to
>> identify v4l2 vb2 and vb1 ioctls and file operations that
>> disrupt the digital stream and would require changes to check
>> tuner ownership prior to changing the tuner configuration.
>> vb2 changes are made in the v4l2-core and vb1 changes are made
>> in the au0828 driver to encourage porting drivers to vb2 to
>> advantage of the new media token resource framework with changes
>> in the core.
>>
>> In this patch v2 series, fixed problems identified in the
>> patch v1 series. Important ones are changing snd-usb-audio
>> to use media tokens, holding tuner lock in VIDIOC_ENUMINPUT,
>> and VIDIOC_QUERYSTD.
> 
> Just took a quick glance over the patches, and my first concern is why
> this has to be lib/*.  This means it's always built-in as long as this
> config is enabled (and will be so on distro kernel) even if it's not
> used at all.
> 

Right this module gets built when CONFIG_MEDIA_SUPPORT is enabled
and stubs are in place when it is not enabled. The intent is for
this feature to be enabled by default when media support is enabled.
When a driver doesn't create the resource, it will simply not find it
and for drivers like snd-usb-audio that aren't tried to media support,
the stubs are in place and feature is essentially disabled.

I picked lib so this module can be included in non-media drivers
e.g: snd-usb-audio.

Does this help explain the design? I didn't want to introduce a new
config for this feature. If lib isn't right place, could you recommend
another one that makes this modules available to non-media drivers?
moving isn't a problem.

thanks,
-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Samsung Research America (Silicon Valley)
shua...@osg.samsung.com | (970) 217-8978
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Re: [PATCH v2 0/6] media token resource framework

2014-10-16 Thread Takashi Iwai
At Wed, 15 Oct 2014 14:21:34 -0600,
Shuah Khan wrote:
> 
> On 10/15/2014 10:48 AM, Takashi Iwai wrote:
> > At Tue, 14 Oct 2014 08:58:36 -0600,
> > Shuah Khan wrote:
> >>
> >> Add media token device resource framework to allow sharing
> >> resources such as tuner, dma, audio etc. across media drivers
> >> and non-media sound drivers that control media hardware. The
> >> Media token resource is created at the main struct device that
> >> is common to all drivers that claim various pieces of the main
> >> media device, which allows them to find the resource using the
> >> main struct device. As an example, digital, analog, and
> >> snd-usb-audio drivers can use the media token resource API
> >> using the main struct device for the interface the media device
> >> is attached to.
> >>
> >> This patch series consists of media token resource framework
> >> and changes to use it in dvb-core, v4l2-core, au0828 driver,
> >> and snd-usb-audio driver.
> >>
> >> With these changes dvb and v4l2 can share the tuner without
> >> disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
> >> vlc audio capture option, arecord/aplay during development to
> >> identify v4l2 vb2 and vb1 ioctls and file operations that
> >> disrupt the digital stream and would require changes to check
> >> tuner ownership prior to changing the tuner configuration.
> >> vb2 changes are made in the v4l2-core and vb1 changes are made
> >> in the au0828 driver to encourage porting drivers to vb2 to
> >> advantage of the new media token resource framework with changes
> >> in the core.
> >>
> >> In this patch v2 series, fixed problems identified in the
> >> patch v1 series. Important ones are changing snd-usb-audio
> >> to use media tokens, holding tuner lock in VIDIOC_ENUMINPUT,
> >> and VIDIOC_QUERYSTD.
> > 
> > Just took a quick glance over the patches, and my first concern is why
> > this has to be lib/*.  This means it's always built-in as long as this
> > config is enabled (and will be so on distro kernel) even if it's not
> > used at all.
> > 
> 
> Right this module gets built when CONFIG_MEDIA_SUPPORT is enabled
> and stubs are in place when it is not enabled. The intent is for
> this feature to be enabled by default when media support is enabled.
> When a driver doesn't create the resource, it will simply not find it
> and for drivers like snd-usb-audio that aren't tried to media support,
> the stubs are in place and feature is essentially disabled.
> 
> I picked lib so this module can be included in non-media drivers
> e.g: snd-usb-audio.
> 
> Does this help explain the design? I didn't want to introduce a new
> config for this feature. If lib isn't right place, could you recommend
> another one that makes this modules available to non-media drivers?
> moving isn't a problem.

We can create a small module depending on CONFIG_MEDIA.  But it'll be
rather a question of the size.  If it's reasonably small and generic
enough, it's worth to put into lib/*, I think.


Takashi
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Re: [PATCH v2 0/6] media token resource framework

2014-10-29 Thread Sakari Ailus

Hi Shuah and others,

Shuah Khan wrote:

Add media token device resource framework to allow sharing
resources such as tuner, dma, audio etc. across media drivers
and non-media sound drivers that control media hardware. The
Media token resource is created at the main struct device that
is common to all drivers that claim various pieces of the main
media device, which allows them to find the resource using the
main struct device. As an example, digital, analog, and
snd-usb-audio drivers can use the media token resource API
using the main struct device for the interface the media device
is attached to.

This patch series consists of media token resource framework
and changes to use it in dvb-core, v4l2-core, au0828 driver,
and snd-usb-audio driver.

With these changes dvb and v4l2 can share the tuner without
disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
vlc audio capture option, arecord/aplay during development to
identify v4l2 vb2 and vb1 ioctls and file operations that
disrupt the digital stream and would require changes to check
tuner ownership prior to changing the tuner configuration.
vb2 changes are made in the v4l2-core and vb1 changes are made
in the au0828 driver to encourage porting drivers to vb2 to
advantage of the new media token resource framework with changes
in the core.


I know this comes quite late after the first patch series has been sent, 
but I'd like to ask if you have you considered a different approach: 
rather than implementing something entirely new, the Media controller 
can almost do this already. It models the physical layout of the device, 
instead of creating special use case specific Media entity like 
constructs for tuner and audio. Also the Media token framework does not 
appear to be as a perfect match for the Media controller framework which 
is also planned to be used by DVB already:


http://linuxtv.org/news.php?entry=2014-10-21.mchehab>; look for "3) 
DVB API improvements". There have been ALSA MC patches as well but I'm 
not aware of the status of those at the moment.


The tokens appear much like media entities of specific kind to me.

Currently, media entities may only be entities bound to a given 
subsystem, but I don't think it has to (or perhaps even may) stay that way.


In case of the Media controller, mutual exclusion of different users is 
currently performed by adding the entities to a pipeline and 
incrementing the streaming count once streaming is enabled --- on 
different interfaces streaming may mean a different thing.


The Media controller interface does not handle serialising potential 
users that may wish to configure the device. If that's needed then we'll 
need to think how to add it.


--
Kind regards,

Sakari Ailus
sakari.ai...@linux.intel.com
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Re: [PATCH v2 0/6] media token resource framework

2014-10-29 Thread Mauro Carvalho Chehab
Em Wed, 29 Oct 2014 11:17:44 +0200
Sakari Ailus  escreveu:

> Hi Shuah and others,
> 
> Shuah Khan wrote:
> > Add media token device resource framework to allow sharing
> > resources such as tuner, dma, audio etc. across media drivers
> > and non-media sound drivers that control media hardware. The
> > Media token resource is created at the main struct device that
> > is common to all drivers that claim various pieces of the main
> > media device, which allows them to find the resource using the
> > main struct device. As an example, digital, analog, and
> > snd-usb-audio drivers can use the media token resource API
> > using the main struct device for the interface the media device
> > is attached to.
> >
> > This patch series consists of media token resource framework
> > and changes to use it in dvb-core, v4l2-core, au0828 driver,
> > and snd-usb-audio driver.
> >
> > With these changes dvb and v4l2 can share the tuner without
> > disrupting each other. Used tvtime, xawtv, kaffeine, and vlc,
> > vlc audio capture option, arecord/aplay during development to
> > identify v4l2 vb2 and vb1 ioctls and file operations that
> > disrupt the digital stream and would require changes to check
> > tuner ownership prior to changing the tuner configuration.
> > vb2 changes are made in the v4l2-core and vb1 changes are made
> > in the au0828 driver to encourage porting drivers to vb2 to
> > advantage of the new media token resource framework with changes
> > in the core.
> 
> I know this comes quite late after the first patch series has been sent, 
> but I'd like to ask if you have you considered a different approach: 
> rather than implementing something entirely new, the Media controller 
> can almost do this already. It models the physical layout of the device, 
> instead of creating special use case specific Media entity like 
> constructs for tuner and audio. Also the Media token framework does not 
> appear to be as a perfect match for the Media controller framework which 
> is also planned to be used by DVB already:
> 
> http://linuxtv.org/news.php?entry=2014-10-21.mchehab>; look for "3) 
> DVB API improvements". There have been ALSA MC patches as well but I'm 
> not aware of the status of those at the moment.
> 
> The tokens appear much like media entities of specific kind to me.

Yeah, it could be seen as that.

> Currently, media entities may only be entities bound to a given 
> subsystem, but I don't think it has to (or perhaps even may) stay that way.

We had some discussions about that with Laurent in San Jose. Yeah,
we will likely need to change that at the media controller, for complex
embedded DVB devices.

The usage of the media controller for this specific usage is that
we should not force userspace apps to be aware of the media controller
just because of hardware locking.

> In case of the Media controller, mutual exclusion of different users is 
> currently performed by adding the entities to a pipeline and 
> incrementing the streaming count once streaming is enabled --- on 
> different interfaces streaming may mean a different thing.

Well, we'll still need to find a way for ALSA to prevent it to use
the audio demod and DMA engine that will be powered off when DVB is
streaming.

> The Media controller interface does not handle serialising potential 
> users that may wish to configure the device. If that's needed then we'll 
> need to think how to add it.

Yes, this would be needed needed if we take this approach. 

Reconfiguring the DMA engine and some other registers via V4L2 API 
should be blocked. The same applies to firmware load, if the device 
is using tuner input for analog TV.

If we use the media controller, we'll need to add a state to it,
to indicate that a block at the pipeline is being reconfigured.

Takashi,

What's the status of Media Controller adoption on ALSA?

Regards,
Mauro
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